Smoke and gas returning means for stoves and furnaces.



E/P. FOLG ER. SMOKE AND GAS RETURNING MEANS FOR STOVES AND FURNACES. APPLICATION FILED FEB. 26, I912.

1,159,934h Patented Aug. 24, 1915.

3 SHEETSSHF.ET I- zfi vb tgoacaz F a H UQ ILFOZ E. P. FOLGER. SMOKE AND GAS RETURNING MEANS FOR STOVES AND FURNACES. APPLICATION HLED FEB. 26. 1912.

1,159,934., Patented Aug. 24, 1915.

3 SHEETSSH ET Z.

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E. P. FOLGER. SMOKE AND GAS RETURNING MEANS FOR STOVES AND FURNACES. APPLICATION FILED FEB. 26, 1912.

1 1 50,93%. Patented Aug. 24, 1915.

3 SHEETS-SHEET 3.

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' EDWARD r. roman, or nounnnnoon, new JERSEY.

. SMOKE AND GAS RETURNING MEANS STOVJES AND lFUEiNACEfs.

Specification of Letters Patent.

Application filed. February 36, 1912. Serial No. 679,823.

To all whom it may concern:

Be it known that I, EDWARD P. FoLGER, a citizen of the United States, residing at Boundbrook, in the county of Somerset and State of New'Jersey, have invented certain new and useful Improvements in Smoke and Gas Returning Means for Stoves and Furnaces, of which the following is a specification.

My invention relates to new and useful improvements in means for returning the products of combustion, including smoke and gases, from a stove or furnace after they have left the combustion chamber to a point where they may be delivered to the combustion chamber to be consumed, the invention contemplating means whereby the smoke and gases may continuously circulate through the combustion chamber whereby the total ormaximum fuel efliciency is attaine'd.

The invention consists in the construction and arrangement of parts to be fully described hereinafter, and the novelty of which will be particularly pointed out and distinctly claimed. 1

I have fully and clearly illustrated my invention in the'accompanying drawings to be taken as a part of this specification and wherein:

Figure 1 is a view in elevation taken in longitudinal section of a structure embodying my invention adapted for use as part of the exit flue of a stove or furnace; Fig. 2

is a'similar view of another embodiment of the same invention; Fig. 3 is a view in vertical longitudinal section of a stove or furnace in which is incorporated a structure exemplifying my invention; Fig. 4 is a longitudinal section through a flue having one form of my invention applied thereto; Fig. 5 is a vertical longitudinal section through a structure embodying my invention adapted to be interposed in a fine pipe of a stove or furnace.

Referring to the drawings by characters of reference, 1 designates a flue pipe leading from a stove or furnace, the same being shown as vertically disposed and-having an open upper end therein. This flue, at its upperend portion, enters the bottom plate 3 of a casing which, although not necessarily, may be formed by a frusto-conical wall 4 closed at its upper end by a top wall 5'having a'central opening 6 in which is sealed in any suitable manner the lower end of a continuation 7 of the fluepipe, the 0011- tinuation forming the outlet for smoke and gases from said casing. In this construction the casing 4 connects the flue sections 1 and 7 so that the products of combustion passing up through the flue 1 will pass through the chamber 4 to the flue section 7 and said casing practically forms part of the flue.

As shown in the drawings, the upper end of the flue pipe 1 projects for a distance Within the chamber 4 above the bottom plate I 3 8, as shown at 8, the projecting portion 8 being provided with an outwardly-flaring flange 9. Supported by this projecting portion 8 of the flue 1 are spider arms 10, upon the outer end portions of which is supported the lower open end of achamber 11 which may be substantially cone -.shaped and of such diameter as to leave an annular space 12 between its wall and the wall of the chamber 4, so that the products of combustion may flow from the pipe 1 into said chamber and down beneath its lower edge and up through the annular space 12 to the flue section 7 The upper; end of the charm ber 11 is closed and terminates short of the top wall 5 of the chamber 4 and is provided with a central opening 13 through which opens a collecting chamber preferably in the form of a conduit 14, said conduit extending longitudinally through the chamber 11 and the upper portion of the flue section '1.

The lower end of the conduit is connected to an imperforate inlet pipe 14 which is directed laterally and projected through an opening 15 in the side wall of said flue 1,.v

the inlet end of said pipe being external of. t e collecting "j v conduit 14 is connected to and communicates with a return pipe section 16 which is v p directed laterally through an opening 17 in g the side wall of the chamber 4-, and then the flue. The upper end of downward, said return pipe 16 being adapted to be connected with the stove orfurnace in connection with which the device, is used, it

preferably beneath the grate. The collecting conduit 14 is provided *Wlfill suitable inlets whereby products of combustion entering the chamber 11' may, under circumstances to be hereinafter set forth, enter said a collecting conduit 14. The inlets just mentioned may take any suitable form, but 1 preferably make them in'the form of slits 19 extending longitudinally of said collecting conduit 14, substantially as shown in Fig. 1 of the drawings. The outer lower 7 Patented Aug. eaters.

- may be established or out OK.

I end of the collecting conduit 14 is provided with any suitable damper 18 by means of which said conduit may be opened or closed. I

5 The pipe section 7 is preferably provided with any form of a damper, such, for instance, as the well-known type of pivoted damper 20, by means of which communica- 1 tion between said pipe and the chamber 4: I may also, if desired, although it is not essential, interpose. in the return conduit 16 a blower or exhauster 21 of any suitable type to increase the draft through said pipe. 5' The parts bein as just described, the operation is as fol ows: If it is not desired that the products of combustion be returned I to. the stove or furnace to be consumed therein, the damper 18 is closed and the damper 2O is'moved to position to establish communication between the chamber 4 and the fiue'section 7, so that the products of combustion, passing up through the flue 1, will enter the chamber 11 and then flow down' under the lower edge of the latter, thence up through the space 12 and the upper end of the chamber 4:, whence they flow out through thefiue section 7. Under the conditions just described, the collecting conduit l4 and the return pipe 16., perform no function, all the products of combustion passing freely from the furnace through the ,flue 1 and the chambers 11 and 4 to the flue outlet 7.

in I t5 Should it be desired to return the prodnets of combustion to the furnace or stove the damper 18 is moved to open the lower end 15 of the collecting conduit 14 to the outer atmosphere, and the damper 20 is opv74,4) erated to cut oil communication between the chamber 4 and the flue section 7. Under these conditions, the draft in the stove or furnace, to which the return section 16 is connected, will cause cold air to flow into a5 theopen end 15 of the collecting conduit,

and thence upward through said conduit into the return pipe section 16. This circulation of the cold air into the collecting conduit tends to create-a vacuum therein which results in the products of combustion being drawn-into the conduit through the slits 19, from which conduit they pass through the returnpipe 16 to the stove. or furnace. The circulation is also eii'ected in part by the fact 7 that the return pipe and'the gases therein I are'of a lower temperature than the heated products delivered into the collector chamber. During this last operation the exhauster or blower 21 may be operated or not,

accordingly as to whether or not sutficient circulation is created by the natural draft of the stove and the inflow of the cold air to the collecting conduit. The primary cause of the circulation is the fact that the as cold air flowing into the collecting conduit le jgh f a vertically extendingfl e the i Y I leaves imam-mam l mt permit at In this form of the invention an outlet con;

in the presence of the highly heated gases in the chamber 11 causes a contraction of the gas in said conduit suficient to draw the i In Fig. 2 a somewhat modified structure is per end of shown from that of Fig. l, the u the inner chamber 11 being close by the up per wall 22 of the casing 23,, which is'the equivalent of the chamber '4, heretofore de scribed,eXcept that it is made substantially so cylindrical instead of conical. In this form ofthe invention the collecting conduit 14% is connected with the return pipe section 16 I through the upper end ofthe chamber 23,, said chamber has its connection with 35",; the outlet flue through its upper wall at a .point eccentric to the point at which the return pipe connects with the collecting cone- 1 iduit, the flue outlet being shown at2 i. The;

and

operation of this form of the invention is substantially identical with that heretofore described, and it is not believed necessary-to repeat the description of that operation here." This form of the invention is particularly adapted for use in situations where thee urnace or stove and the pointwhere it the'use of the form shown in Fig. 1;

In Fig. 3 the invention is shown as tormprovided with a grate 25 anda partition'2d separating chamber 27 and a circulation chamber 28.",

duit or flue 29 extends through an opening in the partitionZG to establish communica- P tion between the chambers 27 and 28, said llu 15 flue 29 supporting a. spider 30 at a distance above the partition 26, upon the outer end of which spider is supported a cone chamber 31, the upper end of which abuts and is closed by the up er wall 32 of the stove or furnace shell. *xtending longitudinally through the cone shell centrally thereof is a collecting conduit 38, the lower end of which is connected to a pipe section 34 extending down through the flue 29 into the combustion. chamber, through an opening 35 in the shell of the stove or furnace, so that cold air exterior to the stove or furnace may be admitted to the conduit 33, the outer end of the pipe section 34 being controlled by a damper 36.

The upper end of the conduit 33 is connected to a return pipe section 37- which is directed laterally, exterior of the stove, and thence downward,

at ing'partof the structure of ast r or fun nace whichjmay be of any's'u table type, the same being shown as consisting of 'a-she'll 24%.; Y

the shell an the main tream;1

- 12o nd thence laterally out where it is connected to 30 and opens through a stove shell beneath the grate, as shown at 38. The chamber 28 opens into an outlet fine 39 which is controlled by a damper 40 to establish and cut off communication between said flue and the chamber 28. It is believed that the operation of this arrangement will be apparent, but it may be briefly stated as follows: When the natural circulation of the stove is to be maintained the damper 36 is moved to closed position and the damper 40 to open position, so that the products of combustionpass from the combustion chamber 27 up through the flue 29 into the chamber 31, thence from the chamber 31 to the chamber 28, from which they emerge through the flue 29, which, it will be understood, communicates with a chimney or stack. If the products of combustion are to be returned to the furnace for consumption, the damper 36 is opened and the damper 40 moved to closed position, so that the cold air entering the pipe 34 flows into the conduit 33. This presence of the cold air in said collecting conduit, as heretofore set forth, causes a contraction of the gas therein, resulting in the heated products of combustion being drawn into said conduit, from which they pass to the return pipe 37 and are delivered to the interior of the stove or furnace beneath the grate. V

In the simplifledform shown in Fig. 4, 41 indicates a flue controlled by a pivoted damper 42 within which, and extending longitudinally thereof, is a collecting conduit 43 provided with longitudinal inlet slits 44, permitting ingress of products of combustion within the flue 41 under circumstances to be presently set forth. The upper end of the conduit 44 is connected to the re-. turn pipe 45, which extends exterior of the fiue and is adapted to have its lower end connected .to the stovein the same manner as the other forms heretofore described.-

' The lower end of the conduit. 44 is connected to a pipe section 46, which extends exterior of the flue, as at 47, and is provided with a controlling damper 48. When the stove-draft is to operate in the usual manner, the damper 48 is closed and the damper 42 is opened so that the products of coinbustion pass through the flue without'the return device operating, but, when it is desired to return the smoke and gases to the stove or furnace the damper 42 is closed and the damper 48 opened so that the cold air may pass through the conduit 44. This causes the products to enter the said collecting chamber 44, whence they pass through the return pipe 45 to the furnace or stove. In this form of the invention the flue constitutes a casing for the collecting conduit.

Theform shown in Fig. 5 is substantially the same as that illustrated in Fig. 1, except that the inner cone chamber is formed with inner and outer spaced concentric walls 50,

51, respectively, forming an annular space 52 closed at its lower end by a wall. 53. The space between these walls communicates with a return pipe 54 leading to the fur- 7c.

nace or stove. The cone chamber is closed at its upper end by a wall 55. p The collecting conduit 56, which ma be of the same form as heretofore descri ed in the other forms of the invention, is shown at 56 and ifv extends longitudinally and centrally through the inner cone 50, said conduit communicating at its upper end through theupper end of said cone 50 with the space 52, and at itsv 1 'i lower end having an imperforate inlet exea tension 57 extending down through the flue 58 to a point exterior thereof, the outer end being controlled by a damper 59. The damper 60' is also used to controi communication between the outlet flue section and the 351 outer chamber, in which the collection conduit and cone chamber are arranged. It is thought that the operation of this form of the invention will be obvioustaking into 'considera-tion the description of the operao tion of the forms heretofore described.

products takes place in each of the embodilooments shown and described.

It will be understood that the damper in the outlet fines or stacks may he of the usual type which permits passage of a limited art of the products even when set to cut v .7

off the draft. It .will also be understood that when the invention is in operation the increased supply of air and the circulation thereof increases the combustion so that the products are reduced to such a degree as to be effectively eliminated in the manner above described.

What I claim and desire to secure by Let ters Patent of the United States is 1. in a device of the character described, 11s

a flue, a perforated collector chamber extending through said flue and in communication with the said flue, said chamber being connected at its upper end to a return conduit opening through the wall of the flue 12c and extending exteriorly of the flue and adapted to be connected to a stove or furnace, and an air inlet pipe connected to the lower end of said collector chamber and communicating therewith, and having an 12s inlet externally of the flue.

2. In a device of the character described, a flue, a collector chamber consisting of a perforated pipe section extending through said flue, an imperforate pipe section conlacv nectedto the lower end of said chamber and having an inlet externally of the flue, and an imperforate returnipe section connected to the upper en of said collector chamber and extending externally of the flue and adapted to be connected to a stove or furnace.

3. In a device of the character described, a casing having a flue inlet and outlet a chamber in said casing into which said flue inlet opens, and communicating with the casing, a perforated collector chamber in said first-named chamber, and having an inlet externally of said casing, and a return conduit connected to the said collector chamber and extending externally of the casing. v

'4. In a device of the character described, a casing, a flue projecting into the base of the casing, a damper controlled outlet from thecasing, a chamber in the casing spaced therefrom, and in communication therewith and into which the inlet flueopens, a per forated collector chamber in said first-named chamber, a return conduit connected to said collector chamber and extending externally of the casing, and an inlet conduit connected to the collector chamber and having an inlet opening externally of said casing.

5. In a device of the character described a casing'having a flue inlet and outlet, a chamber in the casing spaced therefrom and having an open bottom, means for supporting the chamber with its open bottom above the base of the casing and over the flue inlet, a perforated collector chamber Within said first-named chamber and having an inlet conduit connected to its lower end, and opening externally of the casing, and a return conduit connected to the upper end of the collector chamber and extending externally of the casing and adapted to be connected to a stove or furnace.

6. In a device of the character described,

a casing having a flue inlet and outlet, 'a chamber in the casing spaced therefrom and having an open bottom, means for supporting the chamber with its open bottomthe collector chamber and extending externally of the casing and adapted to be connected to a stove or furnace, and dampers for controlling said inlet conduit and outlet 7. In a device of the. character described, in combination, a casing having a flue inlet and a damper-controlled outlet, a chamber supported within the casing and spaced therefrom and having an open lower end spaced above the base of the casing to provide communication between said chamber and, casing and said chamber having a closed upper end, a perforated collector chamber arranged in said first-named chamber, a return pipe connected to the upper end of said collector chamber and extendmg externally of' the casing, and an inlet pipe connected to the lower end of said collector chamber and extending externally of the flue and easing.

In testimony whereof I have hereunto signed my name in the presence of two subscribing witnesses.

' EDWARD P. FOLGER. Witnesses:

J AMES P. SALMON, GEORGE W. LOUGH. 

